Authentication is well known in the computer/cryptographic fields; typical applications are to ensure that another party (or entity) in a communications context is properly identified. An example of such authentication is that distributors of music and video content using the Internet or other computer networks do so using a Digital Rights Management system (DRM) to protect the content from illicit copying and use. DRM is used to protect digital content transferred over a network and transferred from a computer to an associated playback device. The DRM system is implemented by software resident in the host and audio/video player or associated computer. It is often desirable to make sure that the playback device is an authenticated device as part of the DRM system.
So it is known to first authenticate such a device intended to receive such content (or other valuable information) before transmitting to the device any valuable or important information. More broadly, authentication is a way to verify the identity of another device or entity for purposes of sending information to or receiving information from that other entity.